Factorial Calculator

Calculate n factorial for a whole number from zero through 170 and explain the special zero-factorial definition.

Calculate an integer factorial

10! = 3,628,800Product of the integers from 1 through 10.

How this tool works

The factorial of a non-negative integer multiplies every positive integer up to that value. Growth is extremely rapid, so this calculator deliberately caps inputs at 170, the largest factorial range representable as a finite JavaScript number.

For positive integer n, n! equals n×(n−1)×…×2×1. The base definition 0!=1 supports the recurrence n!=n×(n−1)! and counting formulas.

How to use it

  1. Enter a whole number between zero and 170.
  2. Read the computed factorial product.
  3. Check the explanation when using the special zero case.

Worked examples

Ten factorial

Input
10
Output
3,628,800

Multiplying every integer from one through ten produces 3,628,800, a value commonly used in permutation and combination calculations.

Zero factorial

Input
0
Output
1

Zero factorial is defined as one so recursive factorial identities and empty-product counting rules remain mathematically consistent.

Limitations

  • Values above 170 overflow the numeric representation.
  • The output is not an arbitrary-precision BigInt implementation.